1. BIOMARKERS CORE: ABSTRACT The Biomarkers Core provides essential analytical measurements in support of all focus groups of the ChicAgo Center for Health and EnvironmenT (CACHET). The overarching objectives of this Core are to provide CACHET members access to the following: a) routine analytical support enabling determination of exposure to environmental toxins as well as biomarkers indicating the physiological consequences of this exposure; b) new analytical methods and access to resources not previously available to CACHET members; and c) expertise for the design and interpretation of analytical measurements. Core access will be available equally and at discounted rates to all CACHET members, regardless of their institutional affiliation. Types of analyses and services will include 1) quantitative analysis of toxicants (such as pesticides and endocrine disruptors like bisphenol A) in biomedical specimens, and related biomarkers of exposure (including markers of inflammation such as the prostaglandins PGE2 and PGD2 and markers of oxidative stress such as 8-oxo-dG and 8-isoprostane PGF2?) using ultrahigh-pressure liquid chromatography combined with high performance tandem mass spectrometry (UHPLC-MS/MS) in the laboratory of Core Leader Dr. Richard van Breemen at UIC; 2) trace quantitative analysis of semi-volatile organic toxins such as PAHs, organochlorine pesticides, polyhalogenated carbazoles, and halogenated flame retardants in human and environmental samples using gas chromatography-tandem mass spectrometry (GC-MS/MS) in the laboratory of Dr. An Li at UIC; 3) quantitative analysis of metals (including Al, Mn, Fe, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, Sb, Hg, and Pb) in environmental and biomedical specimens by using inductively coupled plasma mass spectrometry (ICP-MS) in the laboratory of Dr. C. Jin Qin at UofC; and 4) characterizing effects of environmental toxicants on the human microbiome in the laboratory of microbial ecologist Dr. Jack Gilbert at UofC. Some of these core resources, such as GC-MS/MS analysis of semi-volatile environmental toxins and effects of environmental toxins on the human microbiome have not been accessible previously to researchers at either UIC or UofC. Due to institutional contributions and CACHET support, these resources will be readily available to CACHET members at substantial discounts. Each laboratory providing services within this core is directed by an expert, and all of these resources will be coordinated by Dr. van Breemen, who has over 30 years of experience in the management of core facilities including MS-based resources.